Not meaning to contradict you, M-A-Canuck, but by "not seat-of-the-pants", I certainly don't mean a runway change can't be fraught and take all concerned to the limits of their abilities! What I DO mean is that assurance of separation is NOT thrown away.
Ludocivo's original post appears to assume that an arrival for the opposite end might be cleared for an approach when their is still the possibility of a go-around from the original end. I hope I can speak for all of us when I say that if an aircraft is put on final to the new, opposite end, when there is still an aircraft on final to the original end, it will NOT be cleared for the approach and it will be kept at an altitude vertically separated from the go-around altitude. Where terrain separation as well as traffic is not an issue, the go-around altitude may be altered from standard to allow a lower altitude, still separated above, for the aircraft on final to the new end, but separation will still be assured until the aircraft in the original direction has landed.